It is well known that one can easily design an adaptive output feedback control system for nonlinear systems satisfying the output feedback exponential passive (OFEP) conditions. In this paper, we deal with a design problem of an adaptive output feedback tracking control for systems which do not satisfy the OFEP conditions. A simple parallel feedforward compensator (PFC) design scheme for non-O...

Feedback connection of (strict) passive systems with multiplicative disturbance on the input of one of systems is considered. Series of conditions are proposed, which provide (strict) passivity property for overall system. These conditions enlarge result from Hill, and Moylan (1977), where passivity property of such connection was established. Applications of proposed results to backstepping co...